[WIP] Jupyter widgets: automatic update of plot options

lib/python/picongpu/plugins/data/base_reader.py

@@ -121,3 +121,38 @@ def _get_for_iteration(self, iteration, **kwargs):
         dependent format and type.
         """
         raise NotImplementedError
+
+    # NOTE: this can be hard to define abstractly since we should make each
+    # parameter query dependent on all other possible choices of parameters
+    # thus requiring kwargs?!
+
+    # e.g. get all species strings for defined values of filter, iteration
+    # and other parameters
+    def get_species(self, iteration=None, species_filter=None):
+        """
+        Get the available species abbreviations for which data exists.
+        Optionally specific iterations and/or filters can be given.
+
+
+        Returns
+        -------
+        A list of species abbreviation strings for which data exists.
+        In case iteration or species_filter are not None, only species
+        are returned that match iteration and species_filter.
+        """
+        raise NotImplementedError
+
+    def get_species_filters(self, iteration=None, species=None):
+        raise NotImplementedError
+
+    def get_options(self, iteration=None, species=None, species_filter=None):
+        """
+        Returns
+        -------
+        a dictionary mapping keywords that a visualizer might use
+        to the values for which data is present.
+        """
+        return {
+            'species': self.get_species(iteration, species_filter),
+            'species_filter': self.get_species_filters(iteration, species)
+        }

lib/python/picongpu/plugins/data/energy_histogram.py

@@ -182,3 +182,9 @@ def _get_for_iteration(self, iteration, species, species_filter="all",
             return data.loc[iteration].values, bins, iteration, dt
         else:
             return data.loc[iteration].values[0, :], bins, iteration, dt
+
+    def get_species(self, iteration=None, species_filter=None):
+        raise NotImplementedError
+
+    def get_species_filters(self):
+        raise NotImplementedError

lib/python/picongpu/plugins/data/phase_space.py

@@ -288,3 +288,22 @@ def _get_for_iteration(self, iteration, ps, species, species_filter='all',
             return ret[0]
         else:
             return ret
+
+    def get_species(self, iteration=None, species_filter=None):
+        raise NotImplementedError
+
+    def get_species_filters(self, iteration=None, species=None):
+        raise NotImplementedError
+
+    def get_ps(self, iteration=None, species=None, species_filter=None):
+        raise NotImplementedError
+
+    def get_options(self, iteration=None, species=None, species_filter=None):
+
+        # the options for species and species_filter
+        d = super().get_options()
+
+        # also append options for ps
+        d['ps'] = self.get_ps()
+
+        return d

lib/python/picongpu/plugins/jupyter_widgets/base_widget.py

@@ -232,6 +232,16 @@ def _handle_run_dir_selection(self, run_dir_selection):
         #    (without triggering the callback)
         self._update_available_sim_times()
 
+        # TODO: update the widgets that allow choosing of parameter
+        # vaues for plotting with the options that are common to
+        # a) the selected simulations and
+        # b) to the selected simulation time
+        # BUT: is this enough to update the options only on choice of
+        # simulations? shouldn't this also be updated when
+        # a) some other option changes
+        # and
+        # b) the simulation time changes?
+
     def _handle_run_dir_selection_callback(self, change):
         """
         Callback function when user selects a subset of the